


Love on the lake

by TheBiPenguin



Category: Teen Wolf (TV)
Genre: M/M, Merman Stiles, Wolf Derek, sterek
Language: English
Status: Completed
Published: 2016-08-26
Updated: 2016-08-24
Packaged: 2018-08-09 15:18:36
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 7
Words: 15,634
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7806937
Author URL: https://archiveofourown.org/users/TheBiPenguin/pseuds/TheBiPenguin
Summary: <blockquote class="userstuff">
              <p>Derek just has to get through one more week of school and he's free. After that, he has no idea where his life will take him. </p><p>That's until a near drowning experience opens his eyes to a whole new world, one too alluring to turn away from.</p>
            </blockquote>





	1. Sounds beneath the surf

**Author's Note:**

> Leona lake is a location in the Eragon series. The mermaid song lyrics are (edited) from the Harry Potter series. If you haven't read both I suggest you put them at the top of your list, they rock!

The Californian summer had transformed Beacon Hills from its’ usual bleak outpost in the north of the state into a pleasantly spacious holiday town. Parents lounged on deckchairs while their children played with water pistols and young couples rode tandem bikes down almost traffic free roads while elderly couples strolled alongside.

And Derek was stuck indoors. He was stuck indoors, again!

He graduated high school in a week, but the day the sun had emerged from its’ winter respite had marked what felt like the longest countdown of his life. Laura had finished college and been back in town for nearly a month already. While Derek sat indoors listening to tedious revision material being droned out by unenthusiastic dinosaurs of teachers, she was in bed until noon, lounging in the sun and shopping about town before heading out for the night with her friends.

Derek was in hell.

He didn’t give a monkey’s about exams. He had no intention of going to college. He had no idea what he wanted to at all, really. Laura had gone down the college route, but he didn’t have a subject he cared enough about to dedicate that much time to and following her through finance and asset management and into the family business with his parents and uncle was NOT going to happen.

His parents had been really good about it, though. They told him that as long as he worked and contributed to the household they didn’t mind and wanted him to be happy, whatever he did. All Derek really knew was that as soon as school was done he was heading straight to Leona Lake.

Leona Lake and the town of Beacon Hills sandwiched the preserve, the former to the south and the latter to the north, with a wide river running down the preserve and town's eastern side, marking the boundary with their neighboring pack. Not that either side really cared, they’d been at peace for over three generations and both crossed the lines and swam in the river without worrying about causing offense.

This is where Derek spent most of his evenings, running in the preserve and swimming in the river. Laura told him he needed a life and the rest of the family agreed. But, Derek wasn’t really involved in the social side of high school any more, he’d outgrown it. He was still involved in the student support centre and basketball team and he had plenty of not-particularly-close friends but the whole prom countdown and lunch-break cliques didn’t interest him.

So this was his life, for now at least. One more week and it was just him and Leona Lake. Every summer his family moved to their modest holiday home by the lakeside. He loved nothing more than the sports you could do on the lake. Kayaking, windsurfing, outdoor swimming. He’d been doing it since he could walk, they all had. Laura had always favored winter sports, like their mother, and Cora preferred track and hiking like their uncle and father. Derek excelled on the water, in the water, all around the water. He'd been leaving his relatives behind in his surf since he was twelve.

But, all that was another entire school week away. It was still Monday and he’d just been released. He left his bag in the Camero outside the house and went straight out for his run, determined to burn off some of his frustration. He took the long route, west up the peaks overlooking the town and round the north side of the preserve to the river, then following it south to the shallow crossing into their neighbor's territory. Even at werewolf speed it was over an hour later when he stood at the base of the familiar wide pine tree laying his folded clothes on the ground. There was no road anywhere near and the human population of the town would never attempt to walk this far off the beaten track.

So Derek didn’t feel overly exposed as he changed into his trunks and walked out into the shallows, savoring the sensation of the sun on his skin as he waded deeper. Once the cool water lapped over his shoulders, he lifted his feet from the pebbled river bed and dived under for a short while. He surfaced with ease, feeling completely secure in his safety as he held his head up above the water with just his leg kick, running his hands over his head to scrape his dark hair away from his face.

“You look like the guy off the Armani advert.” Derek turned to see his sisters in their swimsuits, wading in after him, their clothes chucked carelessly over his.

“Yeah, yeah.” He laughed, the tension of the day already melting away. “And what are you two meant to be, Bondi rescue?”

Laura's response was to dunk him before climbing over his head and swimming off, or trying to. Derek caught her by the ankle and pulled her down after him.

They swam lazily upstream for a few hundred yards before laying back and floating down again then repeating. On the fifth lap Derek misjudged the current and fell under the water. He wasn’t worried. The water was crystal clear in a way not many rivers near large towns are, fresh out of the beautiful Leona Lake. He could see right across to both banks, could see the rays of sunlight twinkling on the surface and diving down all around him. For some reason he couldn’t see the riverbed, they must have been deeper than he thought.

He was about to kick himself back to the surface when he heard it. Under the water it echoed off the choppy waves like a flute played in an empty theater hall. It was a voice, melodic and ethereal. It was a purer, smoother melody than anything Derek had ever heard.

**_Come seek us where our voices sound,_ **

**_We cannot sing above the ground,_ **

**_How long below would you look?_ **

**_To recover what we took._ **

The voice continued to hum serenely, it was all around him. Derek couldn’t locate its’ source. He pulled himself deeper, away from the surface and away from air, heedless to the growing ache in his chest. He wanted to see who the source of that beautiful tune was. Who could have been down here at the bottom of the river since before he’d got in?

As the light faded around him Derek saw a flash of green scales speed across his vision beneath his sinking body. He tried to turn his head after it but he couldn’t match its’ speed. The music ceased suddenly and realization hit him.

He couldn’t breathe!

He tried to make his oxygen starved body shift, to harness the strength he needed to kick back up the twelve feet he dropped away from the lifeline of air he needed. He couldn’t. His lungs were on fire.

He sank further. He was going to die.

His failing brain groped in the dark for a solution. It found none. Just as his body was beginning to turn numb, he felt hands pressed to his chest, blunt, otter-like claws digging into him. The skin on those palms was frigid, as though the water had drained all the heat from them. They shoved him, hard, expelling the last few bubbles from his screaming lungs. He tried to thrash, to fight back, until he realized. The hands were pushing him upwards, back towards the surface, towards life.

As he rose back into the light he saw two amber eyes, wide with panic, staring up into his own fluttering gaze.

They disappeared, all of a sudden, a few feet from the surface and a comparatively warm arm wrapped around his waist and hauled him up and out onto the bank with supernatural strength. As he gasped in greedy lungfuls of delicious air, Laura clapped him across the back with a massive slap, forcing him to vomit  the water from his stomach. 

“What the hell happened?!” She demanded

He shook his head jerkily. “I don’t know.”

\-----------------------------------------------------------------------

“A voice.” Peter repeated doubtfully.

“Singing.” Derek nodded.

The sun had fallen below the trees and the pack had gathered in the cool relief of the evening on the porch in their garden chairs. His sisters had insisted on bringing up the fact that Derek had nearly drowned. He said they were exaggerating, which they were. There was no chance that the person in the river would have let him drown. They’d seen him and been pushing him back towards the surface when Laura had grabbed him.

“Sounds like merfolk enchantment to me.” His father looked concerned.

“We’ve never had trouble on the lake before.” His mother reminded him. “I've ever even seen the Merfolk of Leona. Besides." She turned to Derek "If one of the merfolk wanted you drowned, you’d be drowned.”

No one looked reassured.

“It’s fine, they didn't.” Derek sounded as sure as he felt. "I don't think they realized the effect they were having on me, it wasn't intentional. When they saw me sinking they stopped and pushed me back up. They didn't mean me any harm."

He was certain about it. He wouldn’t have been allowed to drown. He didn’t know how he knew, but, he knew.

"Merfolk magic allows them to charm you.." His uncle spoke slowly, as if too a child. "To paralyze." 

"But I wasn't paralyzed." Derek mimicked petulantly "I just...felt drawn to it. Like it was really important that I find the person singing." 

Laura took a long noisy slurp from the straw of her drink. "That doesn't sound like merfolk enchantment to me." she agreed, shrugging her athletic shoulders, "That sounds like a mating call." 

Derek barked out an involuntary laugh. "That's impossible." He frowned at his mother  "Isn't it?" 

"Not impossible." She conceded. "But certainly extremely unlikely." she smiled in a way Derek was sure was meant to be reassuring.

It wasn't.

"Whatever." He shook his head and got up to go to bed. He still had four more days of crap lessons and three exams to get through. He didn’t particularly care for his results but to squander them now by spending all night musing about a voice his oxygen deprived brain heard at the bottom of the river seemed like a needless waste.

He had some priorities.

"I'm sure it's nothing. I'll probably never see whoever it was again anyway." For some reason, even though he didn't really believe it, the idea made him unduly sad. His sisters sniffed the air in befuddlement but didn't question. 

He hugged each pack mate, rubbing cheeks to reaffirm their bonds, before dragging himself upstairs and crashing out.

\---------------------------------------------------------------

That night he dreamed of the water. He was gliding effortlessly beneath the lake, the glorious midday rays piecing down into its' depths while its' scorching heat was blocked at the surface, leaving him cool and comfortable beneath.

Around him, that tail of emerald green scales swirled, its' owners face indistinguishable except for two  amber eyes, crinkled in the corners as they smiled back at him in the sunlight. Slowly, he and the merperson came to a twirling halt and were left facing each other inches beneath the air. Soft lips reached up to touch his before two hands pressed to his chest and pushed him up through the surface and into the warm air. 

Derek woke with a stupid grin on his face, and the smell of fresh water and reed dwelling birds in his nostrils. 


	2. Leona Lake

**Summary for the Chapter:**

> The Hales head for their lake house for the summer, Derek meets his river bed beauty again and is shown what he really wants to do with his life.

Derek ran and swam every day for the rest of the week, diving for as long as his lungs could cope and swimming much further and longer than he would have normally. Nevertheless. he didn't catch even a glimpse of green scales or amber eyes again. Nor hear so much as a whisper of the song he craved.

When Friday came and went he practically ran from the exam hall.

No prom meant he was already home free. He hadn't really wanted to go, Danny was the only person he was close to and he was going with a date. Derek didn't really feel like third wheeling. he'd been approached by plenty of people, a surprising number actually, girls and guys, who'd wanted to go with him. He'd been friendly with all of them but not wanted to lead them on, and said as much. He'd ended up setting a few of them up with each other in the end. He didn't mind, he was happy for them.

Meanwhile, he'd also managed to convince his parents to drive them out to the lake house that same day rather than wait for the morning and his bag was already packed. 

It was barely a half an hour drive, but, with his sisters it felt like an eternity. Laura, with her long dark locks and regal gaze, had won prom queen when she graduated and Cora was keen to follow in her footsteps. Not wanting to go to prom was an alien concept to them and Derek soon tired of explaining that he was not a psychopath or an monk. When Laura suggested he needed to go to loose his virginity if nothing else his nerves were already a little frayed. 

"I do not!" He snapped. 

That had been misinterpreted, giving rise to an assault of questioning. Derek tried to amend his mistake but his pack laughed so hard he was afraid they were going to crash. He settled for looking out of the window at the passing trees and going beetroot red from embarrassment instead. 

Mercifully, when they arrived, other excitement took over as the two girls fought over the bunks in their room as they did every year and their parents checked out everything in the little outskirt of the town which had changed since last summer. Everything looked the same to Derek, perfectly so. It was the most serene place he knew. A few houses overlooked the lake, their gardens backing onto the preserve. There were no shops, no school, no major roads, nothing. Just a quiet little holiday village on the edge of the town. Its' most prominent feature was the aquatics centre, Derek's home from home. It was a large wooden panel building on the water's edge with long jetties with rowboats moored against them and racks of kayaks in the foyer. 

Derek booked in for a fortnights' activities as a starter, you could only book two weeks in advance. He signed up for all sorts of activities from raft building to lifeguard training. He loved them all and excelled at each of them too. Once he'd finished he walked the few hundred yards around the lakes perimeter to the house. His sisters had finally stopped fighting over space and he was left to unpack his bags in his own room in peace. He stacked his toiletries into the bathroom cabinet, made up the bed and folded his clothes neatly inside the chest of drawers before sprawling back on the bed and switching on his laptop. 

After deciding that revision plus merfolk research was too much all at once, he'd emailed Deaton for an overview. He'd been waiting on his reply with an uncharacteristic impatience he didn't quite know the reason for. It was with unnecessary urgency that he opened the reply he'd received and began working through the poorly chunked essay of information. 

**_Lake Leona is famous for its' supernatural wildlife._ **

**_A family known as the Stilinski's are believed to be the head of the Leona clan. None of their clan members have been seen in 19 years but they're still believed to be present in the lake as there's no reason they'd be deceased and they're not able to leave downriver due to the shallow crossing._ **

**_Not much is known about merfolk, they're mysterious and very mistrusting of landfolk due to previous conflicts. Considered more animal than people by many humans as they lack the ability to speak human languages above water due to difference in the anatomy of their vocal cords, which are adapted to submersion. Many believe them to be supernatural animals with the ability to mimic human language to enchant them (Rubbish)_**

**_While renowned for their ability to enchant and drown landfolk with their songs, very few cases are actually reported. By contrast, sea dwelling merfolk being caught in fishing nets etc is not uncommon, giving rise to the reputation of the merfolk for viciousness and vengeance in response to such accidents, often puncturing even large ships from beneath and sinking them with provocation._**

**_There are a few cases in the literature of merfolk being mated to landfolk, including both vampires and werewolves, where the merman or woman gained the ability to shift into human form following the mate-bite. These are historic cases, none of those mentioned are still alive to confirm the truth of it._**

**_Some sources list the ability to convey protection from drowning among the merfolk's powers. Old myths say that those kissed by a mermaid cannot drown. However, there is little reason to believe that this is true._ **

There was nothing in the email which Derek didn't already sort of know. The merfolk were largely separated from the rest of both the supernatural and natural world by the water-land divide, which was both geographic and linguistic. It wasn't really surprising that so little was known about them. 

Derek didn't know why it bothered him. It shouldn't have. He'd bumped into one of the merfolk and they'd nearly drowned him by accident before realizing and helping him to not die. It should have stayed at that, but, for some reason it bugged him that there was this whole world sitting just beneath the surface about which he knew nothing. Neither did the textbooks and he soon discovered that the internet was full of bullshit on the matter. That annoyed Derek more, having the whole world of research at his fingertips and still an entire race of people had gone under the radar. 

Because, they were people. Very definitely people. The voice Derek had heard had been human, inhumanly beautiful, admittedly, but human nonetheless. The amber eyes he'd seen were too full of awareness to belong to any animal. It wasn't much to go on but Derek was convinced. There was a civilization beneath the water and he wanted to find out everything about it.

The question was how. He had no idea.

Instead he distracted himself with sports, kicking his family's butts at swimming and windsurfing. The long days meant that they were able to get seven full hours in before the sun came down and the centre closed. He was still buzzing with energy as he and the rest of his bedraggled pack made their way lazily back to the house for dinner.

\-------------------------------------------------------------------

Somehow, unlike the rest of the pack, Derek still had a gross excess of energy as he lay awake that night. With the windows wide open to relieve some of the heat which had built up inside the room during the day, he rolled back and forth on top of his duvet. His sensitive ears heard every bird's chirp, every splash on the water. He mentally willed himself to sleep, but, his wakefulness persisted. It was 2am when he conceded defeat. 

Pulling on a pair baggy red swim shorts and a pair of trainers he climbed carefully onto the windowsill, swung his legs out and dropped gracefully down to the ground with a soft thump. He paused, waiting to see if his parents had woken. The house remained quiet. 

Derek smiled to himself as he loped towards the centre. Like everywhere else in the little village, the lights were out, not that the lack of any other light source other than the night sky was really a problem for a werewolf. Derek climbed easily over the high chain linked fence and strode confidently out onto the nearest jetty. Untying a small, one man row boat he hopped in with grace which only comes from years of experience. He didn't bother with a life jacket. During the day with instructors around he had to, but, at night by himself he wasn't concerned. 

It felt good, like working out an old knot in his shoulders he hadn't known was there as his strong back pulled against the handles of the oars, propelling him almost silently away from the shore.He wasn't even close to being out of breath when he reached the centre of the lake and stopped, sitting back against the wooden frame and relaxing in the sounds of his surroundings. it was extremely soothing, so much so that before long his eyes fluttered shut and he almost dosed off to sleep.

He woke with a jerk as the rhythmic splashing of the water against the boat changed. His eyes opened, quickly adjusting in the moonlight, to see the cause of the disturbance gazing back at him. 

It was a woman, or girl really. She was in the water, perched with her elbows on the bow of the boat. She had full red lips and wore a tight fitting, practical vest woven from what looked like pond weed which made her compressed cleavage a distracting sight as she smiled across at him. Her fiery red hair clung to the pale skin of her neck, but, she didn't appear cold. 

"Hello." Derek stammered dumbly. She winked seductively but didn't speak. "Are you...one of the merfolk." 

The beautiful woman nodded, seemingly pleased to be recognized for what she was. As Derek moved closer to sit face to face with her he saw he open gills beneath the angle of her jaw, closed against the air to allow her lungs to take over. Only then did he notice the long webbing between her fingers and blunt claws. Her eyes were glassy, almost fish like, adapted to seeing clearly beneath the water. 

She was not the merperson Derek had encountered in the river. But she was still a mermaid of the same clan. Maybe she knew them, or could at least tell him more about her people. He smiled back at her with as much open friendliness as he could, although he suspected that he looked slightly constipated. She didn't seem to notice, or if she did, she didn't mind. 

"My name's Derek." He blundered on. "What's yours?" 

The mermaid tapped one finger against her closed lips, a silent reminder. "You can't speak above water." He interpreted. She nodded and lowered herself down until she was just beneath the surface, gazing up at him expectantly. He barely hesitated before inhaling deeply and leaning over the edge to plunge his face in after her. 

The water was clean enough for him to discern her facial expression as she smiled again, open mouthed for the first time, revealing long needle like teeth which reminded Derek more than a little bit of a piranha.

"I'm Lydia." Her voice was musical. "It's nice to meet you Derek."

Derek grinned widely, wanting to respond but knowing that he couldn't. Lydia rested her webbed hands on his shoulders to steady herself, calming the motions of her long, red tail as it worked to keep her stationary.

"It's not often we see people out on the water this late." She continued "We usually get to swim unseen. But, you know." She leaned in towards him, whispering in his ear as though afraid that the fish might hear them. "The humans can't know we're here. So since you've seen us, you'll have to stay with us!" 

Derek blew out a feeble shield of bubbles as her claws dug into his skin, trying to pull him into the water. He was the stronger. He spluttered as he pulled himself out of her grasp and stood alone in the wildly rocking boat on the surface. He barely had time to shake the water from his face before a long, muscular figure leaped from the water towards him. It wasn't Lydia, but another, a dark haired male. Derek tried to dodge but had nowhere to go. The male slammed into him, throwing him into the water. 

The air was knocked from his chest on impact. He pushed the merman hard in the chest and was met with the whip of his navy blue tail across his face. He saw a flash of red as Lydia rocketed past his back, the current spinning him uncontrollably. Her partner streamed past his front, then her, then him. They were spinning him in a powerful death roll from which he couldn't escape. He didn't even know which way was up when he felt their four hands seize his wrists and shoulders and began pushing him rapidly away from the moonlight. 

He shifted, claws and fangs springing free. He couldn't get either onto his attackers but he managed to point his legs downwards and kicked with all his might. Their descent slowed and the two predators hissed their surprise, but, still they sank. Derek's limbs felt heavy, as his oxygen depleted they became solid weights, refusing to move to counteract the gravity they commanded. The familiar fire lit in his chest, begging his closed airways to open, to find something, anything to fuel his burning body. 

Somewhere outside his limited field of view, a shriek of anger tore through the water. One of his arms was hauled over his head at the grip on his wrist broke and the dark haired merman hurtled sideways into Lydia. Her hold on him also broke at the impact and both tumbled over each other a few times before splitting and turning back towards him. Derek tried to moved, tried to get away, but could only feebly wave his limbs to little effect, his burned out muscles incapable of movement, powerless to fight back. 

He turned to his attackers, the last faces he would ever see, but, they weren't looking at him. A familiar, lean, emerald green figure glided swiftly beneath him, cold hands cupping his cheeks as soft, pink lips met his. His airways opened without his consent, his chest expanding. The flood of relief would've brought tears to his eyes were he not underwater as he felt the delicious flow of oxygen in his blood, dowsing the flames in his limbs and lungs. Even as his savior's lips withdrew his lungs continued to function. But it wasn't air flowing in and out of his chest, but water. It puzzled him but he was too grateful to care. It flowed in and out of his body with ease, as though he'd been built for it.

His owner of the emerald tail and amber eyes was a pale skinned boy with mousy brown hair and a pond weed belt clamping a dagger shaped rock against his narrow waist. He was stunning, lean muscles emerging from glimmering scales. He wrapped a slender arm around Derek's waist, anchoring him. He felt immediately safe, despite still being fifteen feet beneath the surface. He secured himself by wrapping his own, heavier arm around the boy's broad shoulders as he was turned to face his two aggressors. They kept their distance, the dark hair boy scowled. 

"What the hell are you doing?" Lydia hissed, her beautiful features contorted into a disapproving glare. "You know clan law. Any human who might have seen us has to die. Do you want them to come for us, like in the old days?" 

The boy took Derek's warm hand in his cold one and held it up. Derek's claws were still drawn. "Does that look human to you?" 

Lydia stared dumbfounded, her long flame like locks dancing around her blank face. The dark haired boy frowned. 

"Scottie?" The boy asked. 

Scott gaped as though he were out of the water not beneath it. "Dude. I'm so sorry. We got it wrong. But..." He shook his head. "You just made him undrownable!" He looked at Derek as if he were some kind of immortal. Derek was reassured by the expression of mild alarm he saw there, clearly drowning was the only real card they had to play and Derek had just had it torn up for him by the emerald boy. 

He squeezed him a little tighter in silent thanks. 

"You were going to kill him." Emerald boy waved the arm not wrapped around Derek wildly between the two opposing pairs for emphasis. 

"Stiles." Lydia's tone was calmer now, but, her gaze was like ice. "Scott's right. You should not have done that. You're Dad's gonna go mad." 

"Whatever." Derek felt Stiles' slender shoulders shrug under his bicep. "Least we've got less blood on our hands." He swung his tail lazily, taking him and Derek skywards towards the outline of the underside of the boat. 

"Stiles!" Scott's voice rang clear in the water after them, but neither he nor Lydia attempted to stop them. 

"I'll catch up with you later." Stiles reached the surface and put the heels of both his hands against Derek's buttocks, unceremoniously pushing him up over the side of the boat. 

As Derek broke the surface and landed in the belly of the small boat, he choked out the lungfuls of water he was carrying, flushing out his nostrils harshly, and took his first breath of the night air in what had been a death defying amount of time. When he recovered he sat himself upright and turned to the smiling face of the emerald tailed boy. He was perched on his elbows, much like Lydia had been, but while Lydia had hung back, drawing Derek into the water, Stiles looked as though he had climbed as far into the boat as he could. 

"Thank you." Derek heaved with as much sincerity as he could. Stiles smiled a wide grin of white needles and blew him a kiss. "I'm Derek, by the way." 

Stiles' mouth moved, trying to make Derek's name but unable to produce in the air. Derek couldn't help but laugh as his lips moved clumsily like a guppy. Stiles huffed in his high pitched click and splashed Derek with one webbed hand. 

"Sorry, sorry." Derek brought his laughter under control and moved to sit right up against Stiles, hooking his arms under Stiles' to help support his weight above the water. The boy settled into Derek's arms without question and began tracing one of his cool fingertips between Derek's unwebbed ones curiously. They sat like that for a long while, Derek allowing Stiles to trace over his fingers, gill-less neck and crossed legs in innocent exploration. 

Eventually, Stiles seemed satisfied he'd explore enough and turned his round amber eyes up towards Derek. 

"Did I get you into trouble with your dad?" He asked. 

Stiles seemed to laugh, but it was more of a squeak. Even he looked a little surprised by the noise, clearly unaccustomed to how his body functioned in the air. He shook his head, lifting himself out of Derek's arms and plopped back into the water, stopping himself from going completely under with a ripple of his defined abdominals. Derek leaned out after him but Stiles put one hand to his shoulder, pushing him back safely to sit inside the boat, pecking him on the lips before pulling out of his reach again, pointing towards the shore. 

Derek whined out loud but Stiles simply quirked an eyebrow at him, unfaltering. Derek turned on the seat and picked up the oars to begin rowing back towards the jetty. Stiles swam alongside, holding his torso out of the water effortlessly, seal like, as his tail kept him abreast of the boat. Derek thought it looked as though Stiles was watching his muscles work the oars deliberately, a slight smirk playing on his lips. Despite having been in the frigid water, Derek felt heat flood his cheeks under Stiles' gaze. 

Stiles was exquisitely beautiful, his body hairless and slight. His flawless skin blended at the waist into brilliant green scales. By contrast, Derek thought he must look hulking and hirsute, but whatever Stiles' saw, he seemed to appreciate it. His eyes didn't leave Derek's body until he'd moored the boat and sat on the jetty, his feet hanging into the water. Stiles took Derek's hands and, to his surprise, pulled himself up to rest between Derek's thighs, wrapping his arms around his waist. He smiled up at Derek innocently, obvious to the fact that his face was inches from Derek's groin. Derek supposed that to a merman the groin didn't really hold much significance, so he tried not to let his embarrassment, or his slight arousal, show. 

Not easy when Stiles' soft lips were so close, they sat like that for a moment. Stiles couldn't speak and Derek had no idea what to say. He settled for stroking his fingers through Stiles' wet hair, which seemed to be appreciated. Stile pressed a kiss to Derek's wrist before nodding to the rising sun. 

"It's late." Derek agreed. "I should go." 

Stiles face fell, but he nodded and unwrapped his arms, sinking back into the water. Derek caught his wrist before he could disappear from view, 

"I'll come back tonight." he promised. Stiles didn't respond for a second. "...if you want me to?" 

Stiles frowned in thought for a moment before nodding and lifting up to press kiss to Derek's lips. Derek's quick reflexes recovered enough for him to catch the back of Stiles' head and hold them together for a brief but brilliant moment for him the savor his taste before letting him fall back beneath the surface and vanish. Derek sat for a long time, just staring down into the depths, before getting up and climbing back out of the Aquatics Centre and heading back to the house. 


	3. My little merman

**Summary for the Chapter:**

> Sterek. 
> 
> That's it. 
> 
> (Little angsty towards the end. Fair warning.)

Derek did return that night, he returned every night from then on.

So did Stiles.

Derek always got there first, laid on his stomach with his head hanging off the end of the jetty, nerves on edge worrying that Stiles wouldn't show. He did, every time. He'd slide silently out of the darkness and press his lips to Derek's in greeting. They kissed a little deeper each night, but only once when they met and again when they parted. The rest of the time they spoke. They spoke about everything, anything, all of life. It was difficult, Stiles could only speak under the water and Derek could only speak above it. But, it wasn't as though he was could drown anymore and Stiles' gills seemed easy to close and so his lungs could take over and he could breathe even when his head was laid against Derek's thick biceps as Derek helped hold him up as they spoke. 

Stiles was clever, more clever than anyone their age that Derek had ever met. He'd never been on land, never even left the lake further than the shallow crossing by the Hale house, but, he picked up on the concepts quickly. There were no schools among the merfolk, no cars, no police, no shops, no guns (That part appealed to Derek, if he was honest.) Derek found it difficult trying to describe high school when Stiles had never even heard the word before. While he spoke perfect English, his vocabulary was very limited by the fact that certain things simply didn't exist underwater. 

Derek tried to explain he predicament about college and careers and what he was going to do with his life, but, Stiles didn't really understand why Derek felt the need to commit to anything in particular. In his clan, life was simple. You were taught by your elders, you lived with your family until you took a mate and found your own cavern to adapt into a suitable home. There were no jobs, only clan hierarchy based on experience and skill. Your job was whatever the clan chief, Stiles' father, asked you to do for the survival and betterment of the clan. 

Derek admired the simplicity of it, it was rustic and pure, unadulterated by media or business or politics. But, he couldn't help thinking of all the things Stiles had missed out on. He'd never even seen a map, let alone been on holiday to see the world. He'd never read a book, seen a movie or eaten any of the foods Derek loved. 

Stiles didn't seem unhappy about this fact, but pressed Derek to describe everything in as much detail as possible, from the flavor of pizza to what basketball was. There only seemed to be one sport among the merfolk, which sounded a little like rugby, only with water it meant the pitch was in three dimensions not two as players could move up and down as well. 

When Derek asked about life underwater, Stiles' was generally vague. He became uncomfortable when Derek asked about his father. He eventually confessed that when Scott and Lydia had told them about Derek, his father had forbidden any of them to communicate with the landfolk again. He was livid that Stiles had not only allowed Derek to live, but given him protection from drowning as well. He hadn't wanted to tell Derek because he hadn't wanted to upset him, Stiles clearly had no intention of obeying. 

Derek was more worried that Stiles would be punished for his defiance, he had no idea how strict discipline was among the merfolk. Stiles seemed unconcerned and changed the subject back onto Derek's family. He still had no idea what finance meant or what asset management was and he was refusing to let it go. Not understanding something frustrated him. Apparently, growing up, he and Lydia had been in fierce competition and their war of wits had carried into their near-adult lives. 

Derek's family were actually running rings around him and he admitted as much. He was spending all night with Stiles, then sneaking back just in time for his alarm clock and breakfast then a full day of rowing and running and wresting with each other. He was exhausted, but, he refused to give up even a minute of his time with Stiles, who knew how long it would last? And he couldn't sleep it off during the day without explaining to his family.

He wasn't ready to explain Stiles yet. He didn't really know what he and Stiles were. They weren't really dating, dating wasn't a thing in Stiles' world. Where would you go to for a date? By the sounds of it, courting basically consisted of hunting and making tools etc for your mate to prove your ability to care for each other. 

But Derek felt undeniably drawn to Stiles, even if they weren't dating. He started bringing food to the lake, ordering pizza to the Centre after it closed or bringing him leftovers from the house. Stiles loved all of it, from pepperoni pizza to chamomile tea, he'd found the thermos fascinating and Derek had had to google how it worked for him. The idea of the internet blew Stiles' mind. The thought it was the best thing in the world to have all that information on demand and couldn't believe ordinary humans had invented it.

He didn't like quite everything though.Their first Sunday they discovered that he hated sprouts, apparently some things are universal. Derek had laughed as his little face had scrunched up in sour disappointment when he'd eagerly popped a piece into his mouth. Everything had to be cut up small on account of the fact he couldn't chew. His teeth were designed to grip wet slippery foods so they could be swallowed whole.

Derek was determined to show him as much of the world as possible. He read to him, at first Stiles hadn't believed all that information could be contained within those little squiggles, and played movies of his laptop for them to watch. 

Stiles hadn't understood why Scott and Lydia's teeth had scared Derek, so he'd had to show him the movie Piranha. Stiles had found it both ridiculous and hilarious and they'd barely got halfway through before he began asking questions about what a lifeguard was and why the woman's breasts didn't look a normal shape. Derek had laughed at that one and tried to explain what cosmetic surgery was. Stiles looked appalled. 

In the meantime, Derek's pack were becoming suspicious. His reactions were slow, he was constantly yawning and his appetite had vanished because he was eating a small feast with Stiles each night. His sisters were now kicking his but in his strongest sports, dunking him when they swam and out-rowing him with ease. He didn't really mind, although he did forget to make a fuss about being thrown off his windsurfer and inhaling a lungful of water. That hadn't done anything to dispel their suspicions. 

His uncle was particularly intense about it. His parents largely left him to his own devices and just asked how his day had been each evening, while his sisters made fun, assuming he'd simply lost his touch at sports and that they'd gotten better than him. Peter, on the other hand, definitely knew something was up. He always loaded Derek's plate up at mealtimes, making it obvious that he wasn't really eating. He asked if Derek was sleeping okay in front of everyone as Derek made himself his third cup of coffee of the morning. And Derek was too tired to lie convincingly. His parents must have figured out that something was going on, but, it was Laura who eventually confronted him about it. 

She cornered him one morning. Derek was reaching for the coffee pot when she snatched it out of his reach. 

"Okay. Spill." She said bluntly. Derek shook his head at her, it felt thick with lack of sleep. 

"What?" He puzzled. 

"Why so tired? Why so slow and why are you getting fat when I never see you eat?" 

Derek sucked his gut in involuntarily. "I have not gotten fat." He countered indignantly. He knew he hadn't gained any weight. Stiles was very complementary about Derek's supernaturally crafted physique. Merfolk were built to be compact and streamlined, so Derek's heavy frame and sizable muscles were extremely exotic to him, like some sort of demigod, he'd said. 

"Either way." Laura continued unfazed. "Something's up. What is it?"

"Nothing." He lied. It was a bad lie, but, he didn't have anything better. She heard it. She looked genuinely concerned now, as well as a little hurt. 

"Derek." her voice was soft. "What's going on?" 

He sighed heavily before casting his mind back to the beginning and starting the story. 

\---------------------------------------------------------------

"That's brilliant." Cora sat cross legged on a beanbag in the middle of the lounge, while he and Laura had taken the sofas. None of the adults were home so they hadn't worried about being overheard. "It's like a little mermaid." 

Laura snorted.

"It is not!" Derek snapped. "He's..." words failed him. Once he'd started talking about Stiles, he hadn't been able to stop. From his innocent curiosity to every detail of his body. Derek suddenly realized how much he'd come to know about this boy he'd been speaking to for under a fortnight. Yet now, when he needed to describe Stiles in a sentence, he couldn't.

"Yes it is." Laura laughed, pointing at the stupid grin spreading across his face. "You're stricken." 

"You don't mind?" he ventured. His sisters exchanged a look he didn't recognize. 

"We're happy your happy." Cora began

"But," Laura carried on, her face every part the future Alpha she was. "We want you to be safe."

"I am." His response was immediate. "Stiles would never hurt me." 

"We know." Cora had clearly assumed the role of the good cop. That made Laura the bad cop by their usual default. Derek loved his sisters, but, Laura was undeniably scary. 

"But the merfolk don't trust the landfolk." She warned. "And for good reason, our joined history isn't exactly great." She held her hands up in compromise "You need to know if Stiles' clan is going to be okay if you two do have the mate-spark and you want to become bonded. Otherwise, things could turn nasty when they find out. Plus, we need to tell mum. She is our Alpha." 

Derek nodded. He'd tried not to think about it, but, he knew she was right. He knew his mum would be supportive, but Stiles' clan sounded dangerous. His dad had told him in no uncertain terms that he wasn't to see Derek, much less allow Derek to start courting him. The chief didn't sound like a man to be defied lightly and Derek didn't really know how he'd punish Stiles if he found out. 

"I'll sort it when I see him tonight." He promised. 

Laura pulled him into a rough hug. He hugged her back and Cora flung herself on top and there they sat for a long moment. 

"I love you little brother." Laura rubbed him on the back. 

"We hope he makes you very happy." Cora added. 

Derek was too overwhelmed to reply, he just held his sisters even tighter. 

"And if he doesn't." Laura smirked. "We'll turn him into sushi." 

They all laughed hard at that. 

\---------------------------------------------------

Derek's nerves were as frayed as old rope as he laid on the jetty that night. He'd had to wait later than normal for his parents to go to bed because his mum wanted to watch some movie or other that didn't end until half past midnight. He'd thought Stiles would already be there waiting for him. He arrived at the jetty to the same quiet he did every night and laid down to wait. 

Maybe Stiles had been held up too, Derek didn't really know how the merfolk's sleeping patterns worked. Maybe Stiles had gone to do something else when he'd seen Derek wasn't here yet and would be back soon. He dragged his fingers through the water, making lazy swirls in his own reflection. As the time wore on he started to become anxious. There was so much he and Stiles needed to talk about and this was the night Stiles chose to be late. Derek had to get up after the first hour and began pacing, his distressed brain going into overdrive even in the face of the lack of sleep it had been receiving. 

What would Stiles think of his theory that they might be mates? Would he feel the same? Would he go against his family if they forbade it? Would he want to live or land or would he ask Derek to live in the water? Derek didn't even know where to start with that one, he figured he'd worry about that when it came to it. 

He paced and he thought and he paced and he thought. Still Stiles didn't show. As the sun began to peak above the trees, Derek was forced to concede defeat and with a distinct sense of both disappointment and worry headed back towards the house. 

 

"How'd it go?" Laura burst into his room as soon as he was through the window, as though she'd been listening at the keyhole. 

"He wasn't there." Derek replied miserably, throwing himself down onto the bed. 

"Wasn't he now." Their mothers voice appeared in the doorway. Derek's eyes went wide at the voice of his Alpha before narrowing in suspicion at his sister. Laura shook her head. 

"I didn't tell them. Uncle Peter said something was up. Mum came to speak to you last night and-" 

"And you weren't here." Talia Hale was authority personified and while she'd always been a very nurturing mother, she was an intimidating Alpha. She stood, arms folded across her chest, awaiting his explanation. 

"I...Er..I went to...Erm..."

"To see this Stiles boy?" She tapped her fingers against her forearm impatiently. 

"Yeah." He stammered, panicking now. 

"I did tell her that." Laura admitted. "I didn't really have a choice." Derek managed to nod understandingly. 

"How did it go?" His mother prompted, commanding his attention away from his sister and back to her again. 

"He didn't come." He answered honestly. Keeping things from his parents was one thing, but, lying to his Alpha was beyond unthinkable. "I don't know why." 

His mother heard the truth in his voice and her expression softened. "You normally see him every night?" 

Derek nodded. 

"Okay." She seemed to have come to some sort of conclusion. "Then tonight I'm coming with you. I'd like to meet him." 

Derek's eyes went wide.

"But. He...we..." His mother was already turning her back on him and heading downstairs. Clearly, the conversation was over.

"Get some sleep!" She yelled behind her.

Laura gave him a helpless shrug and then followed her, closing Derek's bedroom door as she went.

Derek laid back onto the bed, filled with a thousand worries and emotions. As he slept he dreamed of Stiles. He saw Stiles locked up under the lake by his clan, saw him speared and gutted by some fisherman and suffering a million other horrible fates Derek couldn't protect him from. He wanted to howl for him, call for his location so he could go to him and check he was okay. He couldn't. He and Stiles weren't mated yet. Could Stiles even hear him under the water?

The worst dream was the last one. He saw a tall, handsome merman. He was the image of Danny, dark and athletic. He was bringing Stiles gifts of otter furs and carefully crafted trinkets. He'd carved a cavern into a comfortable and safe home for them and Stiles had been won over. He'd realized that this nameless man was offering him more than Derek ever could. 

Derek couldn't live with his clan, didn't know anything about life among the merfolk. Choosing Derek would mean leaving everything he'd ever known. Derek had been a fool for thinking that Stiles wouldn't realize that. He was smart, very smart and he'd make the smart decision. In years to come Derek would never so much as cross his mind, he wouldn't even remember his name. 

Derek woke with his face drenched in tears. His claws had sprung free and shredded his bed sheets. He didn't care. He curled himself into a tight ball and cried shamelessly like a baby. He cried until his body shook so hard he thought he'd vomit.

After a few minutes his bedroom door creaked open and his sisters climbed onto his bed. None of them spoke, they didn't need to. Their pack bonds were strong. He had no doubt his parents and uncle had felt his pain too but had chosen to let his sisters handle it quietly rather than make a fuss. Cora lay in front of him, pulling one of his arms down over her shoulders and squeezing his hand between her smaller ones while Laura lay behind him, laying her head down on his shoulder. Having his pack close brought his ragged breathing under control, eventually he drifted back to sleep. It was still a restless sleep, but at least the nightmares stayed at bay.


	4. Where is my wolf?

**Summary for the Chapter:**

> Stiles and Derek find that absence really does make the heart grow fonder.

Stiles swam in furious circles. He tired to jump to freedom, but there was no other water around, just land. He collided with the clear bank of the pond he was in, again. It was glass. He'd seen glass before, bottles and stuff, but this was different. One whole bank of the tiny pond was made of it and he could see the landfolk dressed in their khaki trousers and matching green T-shirts stood on the other side talking. He couldn't hear what they were saying but they looked far too happy. He hissed at them venomously but they didn't even flinch. They knew he couldn't get at them. 

He swirled again in another tiny circuit of the pond. The water tasted strange on his gills, not like Leona. It was also tainted with his blood, the marks in his sides still raw from the net he'd been snared in. He slammed into the glass again, gaining the landfolks attention as he beat his tail and scratched his claws against the invisible barrier. They frowned at him, as though they were mildly worried, rather than feeling the outright terror he'd been aiming for. Not one of them moved to act, not the skinny old man with the thinning pony tail and scraggy beard or the woman covered in blubber with curly blond hair. There was a very important looking man with pinched little features atop reddened cheeks, he seemed to be speaking at some length and all the other brainless landfolk were hanging on his every word. 

He swore to them that he would drown them all and that the lake mother would hold their souls breathless beneath her waters in eternal torture. He swore that he would drown them and strip the flesh from their bones. They couldn't hear him any more than he could them, so he flashed his teeth in his best piranha impression to make to point. They gasped in some grim amusement at his threat. Little did they know. 

He would not live like this. He would not die like this. 

But they would. 

Stiles had been raised on cautionary tales of merfolk who'd fallen foul of humans. Butchered for food or imprisoned and made to perform inane tricks for their dumb entertainment. They were the horror stories of his people and now he was trapped in one of his own. 

Stiles brought the futile beating of his bruised tail to a stop. He was scared. More scared than he'd ever been. 

He wanted his dad. He wanted Scott and Lydia. He wanted his clan to come to his rescue, to help him break the glass bank and drown the wicked humans together.

More than anything he wanted Derek.

Derek knew the land. He would find him. Derek had said that the land was much much bigger than the lake but how far could he have been taken, really? How far away was Derek? Was he looking for him or did he think that Stiles had abandoned him? 

No. Derek would know that Stiles wouldn't do that. They were soul-matched. He knew it, even if neither of them had said it yet. Stiles had heard stories of merfolk being soul-matched with landfolk and going to live with them above the water, shifting from human to fish with a unique talent no merfolk could be born with. 

Derek would find him. He knew he would. Or at least he hoped that he did. As he scanned the faces of the landfolk pressing their ugly features against the glass bank of his pond he screamed the same question, hearing it bounce around inside his prison unheard, futile.

_**Where is my wolf?** _

\-----------------------------------------------------

That night, Derek left to see Stiles through the front door. 

It felt wrong, like he was a naughty child who'd been caught and was now being made to lead the grown ups to his partner in crime. Logically, he knew this was unfair. His mother was responsible for his safety as his Alpha as well as his mother and she took that very seriously. Derek desperately hoped that she liked Stiles, that she'd say she didn't care what the clan chief said or anyone else and that Stiles would be welcomed as pack if he asked for it. Derek didn't know how he'd cope beneath the water, if he was forced to follow Stiles under.

He'd do it, if he had to. 

In that moment, walking with his mother towards the aquatics centre in the moonlight it dawned on him, like the most unnecessary epiphany. He would do anything for Stiles. He'd leave his pack and live in the lake. He'd fight off his entire clan. He'd carve out the biggest cave he could for them to live in together and dedicate all his time to learning how to make the things Stiles needed and liked.

When they reached the centre his mother came to a halt and looked to him expectantly. Dressed in loose jeans and trainers Derek climbed the fence with ease. His mother huffed in annoyance. She'd worn skinny jeans and heeled, calf height boots. 

"You could've warned me." She deadpanned as she hauled herself over and landed beside him. 

He smiled but didn't reply. She understood. She knew that he already had a million and one thoughts and feelings vying for his attention and she didn't want to add to them. When Derek sat cross legged on the end of the jetty to wait for Stiles she sat beside him quietly without question. They sat like it for over an hour before Derek broke the silence. 

"I'm worried about him." He blurted. 

"Okay." His mothers voice was neutral. "What is it that worries you?" 

"I'm worried something's happened to him." Derek's voice broke, he sniffed loudly. His mother put a hand on his shoulder and squeezed it gently. 

"What reason do we have to think something might've happened to him?" She was doing what she did best, being the voice of calm reason. He appreciated it now more than ever. When he couldn't answer she did it for him. "Not coming to meet you means one of two things. Either he couldn't or he didn't want to." She didn't say it with malice, but the words cut Derek to his core. 

"What do we do?" he turned his glistening eyes to her, like a puppy seeking comfort in her advice. 

"I don't believe Stiles has chosen not to show up." She began. "From what Laura told me I think he'd have said something first." Derek took a shaky breath. Stiles abandoning him was awful but at least it would mean he was okay, even if it was without Derek. 

"Which means for whatever reason he can't." She concluded. "But the merfolk aren't monsters and Stiles is the Chief's son. They wouldn't hurt him. Maybe his father has found out and is refusing to let him come." 

That was a best case scenario and Derek knew it. Even that was horrible. 

"What do we do?" He repeated. 

His mother blew out a long breath before answering. "I don't know." She confessed.

 

"Nothing?" Peter frowned deeply at his sister. "All night?" 

"Not a peep." She confirmed. The pack had gathered in the kitchen, no one had really slept. They all held cups of coffee and munched on buttered toast as they spoke. 

"I'm worried." Derek whined for the hundredth time. 

His father slung an arm over his shoulder. "If Stiles' father has forbidden it Der, I don't see how we can get around it." He admitted. 

Derek shook his head. He wasn't giving up that easily, not on Stiles. 

"You don't even know him that well." Peter pointed out. "This isn't Romeo and Juliet, Derek." 

Derek growled at his uncle, a deep, guttural noise he'd never made before. He hadn't known Stiles very long, that was true, but he wasn't just being some stupid teenager about this. He knew he couldn't love Stiles, not this quickly, but, there was something between them. A spark of something special he refused to just let go of.

If Stiles told him to let him go, then he would respect that. Until then, not a chance. 

"Keep going back." Laura cut in. The whole pack looked at her. She casually flung her long, dark locks over one shoulder and took another mouthful of coffee before explaining. "It's the only card we have to play." Derek didn't miss the change in pronouns. They were pack and they were in this together. He loved them for that, even Peter. 

"One of us has to go with you." his uncle warned. "You may be undrownable but there's more than one way to get killed in a lake." 

Derek nodded. He would go back. He'd keep going back until eventually Stiles either got away to see him somehow or decided it was time to come and put Derek out of his misery. 

Either way he was going back for Stiles. 

For his Stiles. 

\-----------------------------------------------------------

Stiles sat quietly at the bottom of the pond, seemingly asleep. 

It was early, the landfolk in their matching green clothes were just arriving. The same one came every day. He was an old, blubbery man with oily skin and what Stiles now recognized as cigarette stains of his fingers.  

He stank. And he was ugly. He had a flushed red face and round glass eye protecting things on top of his big, red nose. 

Worst were his teeth, his mouth looked as though something had swum into it and died. Stiles couldn't smell his breath from underwater and was extremely grateful for the fact. He hated this man more than the others. This was the man in charge of Stiles' pond. He put the horrible taste in his water and lit the small, fake suns above the pond every day, exposing him through the glass bank for the other landfolk to jeer at. 

He brought Stiles his food, but not out of kindness. Derek brought Stiles new foods to try because he wanted him to have nice things and he was trying to court him. This man fed Stiles just to stop him from starving because they needed him alive.

But Stiles had no intention of starving. 

If there was one thing he'd learned about these humans in particular is that they were creatures of strict habits. They arrive at the same time, they do the same things in the same order at the same speed and then they turn off the fake suns and leave at the same time. It was unbearably tedious. Stiles could only assume that they had the mental capacity of pond weed. He couldn't think of any other way to survive such drudgery. 

The fake suns lit up as usual and the hated man waddled up the loud metal steps which led up the pond's rear bank and over the water, As he stomped his sweaty feet along he sang to himself through a mouthful of fries. 

 

_**1,2,3,4,5** _

_**Once I caught a fish alive** _

_**6,7,8,9,10** _

_**Then I let him go again.**_  

 

Took a handful of the flavorless fish from the icebox above the pond and, walking to the edge, began to throw them in.

 

**_Why did you let it go?_ **

**_Because it bit my finger so_ **

**_Which finger did it bite?_ **

**_This little finger on my RAARRRRGHH!!_ **

 

From almost directly beneath him, a webbed hand shot from the water and seized one thick, hairy ankle and pulled hard. He fell with a clatter against the metal framework, his head cracking loudly against the railings and all went quiet.

A dark smear of blood was spread across the landing from the steps to the water's edge as the man's limp frame was dragged feet first into the water without a struggle. The last ripples faded and the pond returned to silence, save for the victorious chuckle of its' unconsenting occupant. 


	5. Let me go

Stiles refused to jump. 

He could see the fish, hung over the water just out of his reach in the centre of a striped red and white hoop. He was starving. 

Still, he refused to jump. 

He was weak from hunger, after the incident with the drowned man they'd not fed him for nearly a week. Now, they were only going to give him food if he was willing to jump up and get it. He knew how this worked. Once he'd gotten used to jumping though the hoop for food, they'd make him doing in front of the other landfolk. Stiles was not some dumb animal. He wouldn't jump. 

He popped his head out of the water and hissed at the two landfolk, the blubbery, blonde woman and scrawny, ponytail man. They were both stood well away from the edge, far out of his reach. He narrowed his eyes and bared his many teeth at them. 

"Come on, sweetie." Blubber woman cooed, her voice sickly sweet. "You can make that little jump." 

Did she think he couldn't understand her? Stiles would've found that both fascinating and hilarious had the situation been less grim. Gathering his remaining strength he leaped completely clear of the water, snapping his tail and casting a wide arc of water over the pair of them, before diving back under. Scrawny looked angry, but, Blubber simply looked amused. 

"That was good." She encouraged. That annoyed Stiles more. 

"Not through the hoop though." Scrawny pointed out. 

"He will." She assured, leaving the hoop in place she turned and started back down the metal steps and out of Stiles' sight. "I know he will."

Scrawny cast Stiles one last contempt filled look before following. After a long wait, to be absolutely certain they were gone, Stiles leaped up and snatched the fish from the air, falling unceremoniously through the hoop in an attempt to abort the leap. 

He didn't waste time grieving his pride as he tore into his meager meal. It tasted of nothing and made his head thick. All the food they gave him did that now, made him slow and lethargic, but, he had to eat. 

He'd get them, too. Just wait. 

\------------------------------------------------------------

Derek went back to the jetty every night. 

Now his pack knew about Stiles, he'd cancelled all his day activities so his could sleep and went out every night. The pack took turns coming with him. The fourth night was Peter's turn. Derek had hoped that Stiles would show on a night his uncle wasn't with him, but by the time they saw the sun rising over the treetops, Derek would've endured anything Peter could've said or done if only Stiles would come back to him. 

Derek knew something was wrong. He knew it. 

His mother had been right when she said that Stiles wouldn't have just dropped Derek without telling him. From what Stiles told him nothing much happened on the lake without the Merfolk knowing, so if they'd found out about Stiles and Derek then they knew Derek was coming here each night. Even if Stiles was forbidden to see him, why hadn't Scott or Lydia been sent to send Derek away, or kill him? Were they that afraid of him just because he couldn't drown? Derek didn't believe that for a second. 

Whatever the truth, the Merfolk would know what had happened to their chief's son, whether it was their doing or not. Their not telling him angered Derek more than anything. He wanted Stiles back, for sure. But, more than that, more than anything, he wanted to know that Stiles was safe. Peter had tried the whole "If you love them, let them go." speech. It hadn't worked, but, why hadn't the merfolk come to try that on him yet?

It worried him. More than Stiles' absence. If the clan weren't responsible for Stiles' disappearance, why weren't they asking for his help? Did they suspect Derek?

"More likely." Peter mused. "Is that they're either keeping him away themselves, or they don't think you can help get him back."

Derek didn't like that answer. It stank of death or despair. He tried to put it from his mind. Stiles couldn't be dead, Derek would've felt it. But what could've happened that the Merfolk would give up on one of their own as lost? 

Derek liked the many possible answers to that question even less. 

\-----------------------------------------------------------------

"No, thanks." Derek put the leaflet back on the kitchen counter. "You guys go."

"Derek!" Laura whined. "It'll be fun." She took him by the shoulders. "I know you're upset right now, but, all you do is sleep, eat and wait. It's not healthy." 

"I agree," their mother added. 

"You don't need to sleep ALL day." Laura continued. "Sleep in the morning, we'll go in the afternoon. I promise we'll be back before sundown." 

Derek looked over the leaflet more thoughtfully. North California Supernatural Wildlife Centre. An exotic zoo, basically. The leaflet read Grand Opening, with magnificent griffins sawing overhead and a black basilisk slithering along its' bottom edge. It did look like fun. Cora had always loved the zoo and Derek loved whatever made his sisters happy. Personally, he'd always preferred the National Parks. 

"Alright." He said. "It does look like fun. Let's go." 

Laura gave a small victory cry and clapped her hands excitedly before pulling him into an overenthusiastic hug. He hugged back, if a little reluctantly, before being released. 

"It'll be good for you to have something else to think about," His mother stroked his cheek gently. "Just for one afternoon." 

He nodded, there was nothing he could do for Stiles during the day. There was no way the Merfolk would approach him with information in broad daylight when the Aquatics Centre was full of people. That didn't make him feel any less guilty for going out and having fun when he still had no idea where or how Stiles was.

"I know." He conceded. 


	6. Give me what's mine

**Summary for the Chapter:**

> Derek gets possessive.

The Supernatural Wildlife Centre was a full two hour drive away. 

It was an obscenely hot day, even for North California, and the canine style panting was prevalent enough among the pack members than any risk of joke making had been eliminated. Derek insisted on having a window seat in the car and had said window rolled all the way down for the duration of the drive, his sweaty skin still plastered against the leather. The heat was such that if he and Laura had hung their heads out of the car to catch the air, their parents would have probably forgiven them their disgrace. 

It was with a great sense of relief that Talia parked and released them into the days meager breeze. They stood for a moment, letting some of the trapped heat soak out of their skin before starting towards the centre's large front gates. 

The leaflet had said "Grand Opening" and it had been true to its' word. It was an enormous site, Derek couldn't see an end to it in any direction. Five rows of parents and grandparents, all with overexcited children in tow. stood lined up at the high, iron gates to reach wooden paneled ticket booths. Cora groaned loudly at the sight, but, the centre management must have planned the day well because they joined a queue at random, they were all of similar length, and had been sold their tickets within a few minutes. This was in no small part due to the hyperactive, broadly grinning eighteen year old manning the ticket booth. His green polo was damp with sweat, emphasizing his unfortunately adolescent-typical skin. Derek smiled kindly as the boy tied the wristband around him, holding his palm between his for a subtle moment longer than necessary, before following his sisters into the entrance courtyard. 

It looked every part a cliche zoo. There were tall trees lining the wide walkways, which lead in a thousand directions like an open air labyrinth. Daring children cautiously strayed into their shadows before screaming in delight and running as the branches whipped around to ward them away. Derek smiled. They'd taken a holiday in San Diego years ago where he and Laura had spent over an hour playing the same game, testing their growing supernatural speed against the saplings. 

Laura, now taller, stronger and much more beautiful than her dorky childhood self, was oblivious. Cora had climbed atop the back of a large statue of a unicorn and she was taking a photo on her phone. Their parents had unfolded the map in traditional organized parent style and were busy deciding on a route around the various paddocks to ensure everything got seen. Peter stood with his hands in the pockets of his jeans, looking a little lost, but happy nonetheless. 

Eventually, their parents came to some agreement he couldn't hear and shepherded them off down the walkway to the right. Derek smiled at his mother amiably as she linked her arm with his, giving him an affectionate squeeze. 

"It looks really good here, doesn't it." She beamed.

He hummed his agreement, but he wasn't listening. Ahead where Cora and Peter raced each other towards the ice cream stand was a wide circular fountain into which people were tossing pennies. In its' centre, water spouted upwards towards the blue sky before running down the lean physique of the crowning statue. It was a merman. His medium length hair flying about his face as he leaped, seemingly from the shallow disc of copper filled water beneath him. 

\--------------------------------------------------

Cora loved all of it. They all did. Even Derek began to loose himself in the easy lightheartedness of it all. 

The centre boasted a large diversity of supernatural creatures, great and small. The reptile house had indeed had a basilisk, three in fact. They'd had to wear eye protectors to be allowed in to see them, under strict instructions not to remove them for any reason. That had made Derek nervous and of course as soon as Laura smelled that she had volunteered him when the heavily tanned keeper in khaki shorts had asked who wanted to have the largest one wrapped over their shoulders for photos. That had been, quite frankly, terrifying, but the adrenaline shot did help improve his mood. 

As the afternoon drew on and the heat waned, he began to forgive himself. His pack had been right, there was nothing he could've done during the day, the merfolk would never have come near him. He'd go back tonight, he'd keep going back until one of them told him what had happened to Stiles. The thought made Derek sick to his stomach, but, it was pushed from his mind as his father placed a white paper bag of animal feed into his hand. Derek frowned at it, confused. 

"Phoenixes" Jason smiled, clapping him on the back. "You loved them as a kid, you know." 

Derek laughed, moving over towards a large orange sign hung over the path marked "Aviary". 

Their mother guided them with expert ease, the result of many family outings with far younger and more unruly versions of her children. They fed the phoenixes and eventually saw one of the moor cats, a charcoal grey feline with nimble limbs and powerful jaws. They didn't see it exactly, Laura had given up looking vainly through the brush of the enclosure and stood leaned against the glass, texting, while Derek and Cora had persevered. Eventually, the cat found them, pouncing out of nowhere at Laura and colliding with the invisible barrier. She'd jumped away at such speed she'd fallen clean over onto the pavement and sent her phone skittering away towards the griffin enclosure on the far side, causing her siblings to collapse with laughter at her indignation while the disappointed predator stalked back into invisibility. 

They'd almost walked the lap of the centre and Derek's feet were aching in his sneakers. Cora had lost none of her energy, but the rest of the pack were flagging. The zoo's many human visitors were sprawled on picnic blankets and benches eating sandwiches out of carefully stacked Tupperware. The main gates were back in view when Derek heard the unmistakable noise of running water. 

Between them and the exit was a side path which led down and out of site beneath a large tank, the occupant of which Derek couldn't see. The arch beneath the tank read "Creatures of the deep." 

He'd hoped he'd be spared this exhibit. He did not want to be around the water, looking at blissfully unaware marine creatures safe in their tanks while Stiles was god only knows where. He wasn't spared. He followed his sisters down the ramp and into the artificially lit aquarium. It was a relief to be out of the sun, which even in the late afternoon was still a burden to be under. The tanks were larger than he expected, their glass filling the room from floor to ceiling as children pressed their faces against the glass to awe at grindylows squabbling over gemstones with their many arms and crystal blue, dwarf-sea dragons gliding between heated rocks.

They were beautiful. But none as beautiful as the prince of the water that Derek was yearning for. A flash of green in the corner of his vision turned his head. At the far end of the exhibit, near the exit, was a slightly larger tank. It's occupant had whisked out of sight. The labelled description was too far away to read but the carvings leaning outwards from the aquarium walls spoke volumes. They were fierce, tailed hunters wielding tridents against giant squid and hugging bliss faced human partners as they swam down towards the floor. 

Merfolk. 

Derek frowned. That couldn't be right. Curiosity carried him halfway to the tank but as the resident glided back into view Derek felt himself propelled forward to slam palms and face against the glass, his expression cleared of all belief. He almost thought he was hallucinating, so desperate his brain had concocted the image to placate him. The merman wore a vacant expression and slow movements he didn't recognize but that didn't make him any less certain. 

"STILES!" He yelled at the top of his voice, slamming his fist against the tank. Still Stiles continued the tiny, lazy circle around his cage. Derek drew his arm back to hit again when Laura caught his wrist. 

"What the hell are you doing?!" She hissed. 

"It's him!" Derek nodded at the tank, barely able to string the two words together as adrenaline poured into his blood. 

"What?" She dropped his hand just as Cora reached them and saw the prisoner behind the glass for the first time. 

"Why do they have a merman!" Cora sounded shocked, her hand clasped over her mouth. 

"Stiles!" Derek hit the glass again, to equally little effect. He didn't see the realization dawning on his sister's or hear the angry shouts of the approaching keepers, telling him now to bang on the glass.

He roared. He expelled a noise into the world he didn't even know he could make. It was charged with pure fury, an outrage beyond anything he could describe. His sisters jumped away from him and his claws sprung free, digging into the glass. Stiles snapped his head up in attention as the message rang in their ears. 

_**GIVE ME WHAT'S MINE!** _

It was possessive and filled with protective instincts that were beyond fear and beyond uncertainty. It was the call of mates. 

Cora rounded on the nearest keeper, "What the hell is that?" She jabbed a finger at the tank. The man looked bewildered. 

"We keep a wide number of exotic animals, miss. We ask that you don't distress-" 

"That is NOT an animal, dumbass!" her voice dripped in condescending menace.

The man drew himself tall, pushing his round glasses up his nose before speaking about legal definitions of animals vs people. Derek didn't hear. 

Stiles was face to face with him, suspended in the water as though on the other side of the universe looking across the void at him. Their palms were pressed together, their faces reading the same paled look of mortification. 

Derek tore his gaze away and stepped to the side, where there stood a windowless door marked "Staff Only." He kicked it and the lock gave easily, the wood splintering beneath his shoe. There were shouts for security as he leaped up the metal steps two at a time, his sisters at his side, and knelt over the water. He saw Stiles spin beneath the surface, disorientated, before surfacing beneath him. Derek caught him under the arms and held his dead weight up as feeble arms wrapped around his neck. Stiles' gills slid shut and Derek nuzzled directly beneath his jawline where they had been, wanting to take him in with every sense to be sure he was real.

At the bottom of the steps, the keeper shouted up at them in alarm. "Sir. Step away from the water! That Merman has already killed one keeper-" 

"Yeah and I'll kill the next one!" Laura bared her fangs and the man backed off out the door and out of sight to await security. She dropped to Derek's side, one hand on his shoulder. "They've called security, Der. We haven't got long. You gotta plan?" 

To his own amazement he nodded, feeling Stiles' unbalanced head loll against his shoulder. He shook him, a little forcefully and his eyes fluttered open to meet Derek's. His look was giddy, drunk almost, but they didn't have time to question it. 

"Stiles. Stiles, listen to me!" He'd never begged for anything so hard in his life but right now he needed Stiles to be present here with him, if only for a second. "There's only one way they're gonna let us take you out of here and that's if you can walk out. Do you understand?" He wanted to just do it, to do what was necessary to protect him. He would, if he had to. 

Stiles nodded with a slow realization. He pressed a soft kiss to the corner of Derek's mouth before letting his head fall sideways to expose his neck. Derek drew in a breath he bared his fangs, carefully leaning around the slender creature in his arms to avoid major arteries and veins and bit into him, feeling his muscles snap taught in response.

Two tall security guards barreled through the door behind them. He heard his sisters snarl in response, not budging an inch. 

"Sir. Turn around and put the animal down." a deep voice commanded. 

Slowly, Derek rose to his feet, his merman still in his arms. "He's not an animal." He declared with equal command. He turned and lowered Stiles onto his shaking legs, because he had legs now. His sisters were smiling back over their shoulders, in spite of the two guns being pointed at them, at the gill-less neck and unwebbed fingers. He felt the smooth skin of Stiles' thigh leaned against his where before his tail had hung. 

Both keepers and guards wore matching expressions of disbelief. Derek turned to Stiles, wanting to give him a smug look, but Stiles was leaned on him in a state of almost completely collapsed and didn't realize. Derek shifted them so one of his arms was wrapped around his mates waist, splinting them together. He looked up as his parents and uncle stepped into the room, growling at the two men pointing weapons at their children. 

"What you gonna do?" Laura mocked. "Shoot us?" She moved a step lower but the guns didn't lower. "We're all humans, asshole. Can't stop any of us walking out of here." She wore the confidently victorious smirk of the rising alpha she was and she wore it well.

He and Cora followed her passed the gathered staff members, who stood frozen with indecision, and out into the daylight. Out of the water, Stiles seemed to be becoming more alert, his head held up and swiveling about nervously. Derek lifted his chin and rolled Stiles in towards him as they walked, aware for the first time of Stiles' nakedness. His mate seemed oblivious but people were staring. Derek wanted to tell them all to get fucked but he was too focused on half carrying Stiles out to the car before anyone questioned them. Stiles' legs were still all but useless, he had no idea how to control them. Derek lifted him into the back seat and settled in next to him, hugging him close as he fastened their belts. 

"I'm taking you home." he promised, kissing the increasingly warm skin of his cheek. He was shifted completely, his body flushing with hot blood to dispel the chill of the water. 

"I'm taking you home." 


	7. Home

**Summary for the Chapter:**

> It all comes together.

It was nearly dark by the time the car pulled up outside the aquatics centre on Leona lake.

Derek had refused to take his arms from around Stiles the entire journey, except for one moment when his parents had brought them two of the wildlife centre's long sleeved shirts from the gift shop. Derek had cringed at seeing the logo printed on the chest initially, but helped tie them into a makeshift skirt to cover Stiles' new anatomy. He'd been too stressed out by the whole situation at the time, but now, the memory of said anatomy seemed determined to stay center stage in Derek's mind. 

Stiles kept hold of Derek's hand. As the journey wore on he became more alert, more like the Stiles Derek recognized. He told them what had happened, that he'd been in the river where he and Derek first met, resting in the sun in the shallows, when he'd be netted and that he'd been living in the tank ever since. He didn't give away any details and nobody asked. Derek decided that, when they were alone, he wanted to know exactly what was done to his mate, to help him come to terms with it properly. 

Stiles didn't say it but Derek could hear it in the tone of his voice, resignation tinged with disbelief. Stiles had thought he would live out his days in that tank, made to jump for dumb amusement like a circus animal. He told them that the food had made him woozy, a drug no doubt. The mate bite had transformed his body and with it his metabolism, clearing the drug from his system within minutes. 

Stiles' scent had improved too. It wasn't just Derek's bite in his blood, exhaling their mixed scents through his pores. His breath had smelled sickly sweet when Derek first lifted him from the water, like he'd drunk too many energy drinks. It was fresher now, cleaner. Derek took that as a good sign. 

His pack dropped them off outside the centre, leaving them on the front steps. They each hugged Stiles warmly, rubbing cheeks as pack mates do. Stiles was practically crying, he seized each of them in what should have been a bone crushing embrace. He must have said thank you over three dozen times before the pack got back in the car and vanished out of sight. 

Only then did Stiles' attention turn fully to Derek. As they stood facing each other by the side of the road, Derek's heart pounded against his ribs as though desperate to escape from his body away to its' new owner. Said boy smiled in blissful innocence at him with his new mouthful of flat, white teeth. It made Derek break out in his own goofy grin. 

Stiles put the warm palms of his hands against Derek's cheeks and kissed him. It was different to any of the kisses they'd shared by the lake before. Stiles pressed gently but insistently against him, like he was trying to read Derek every romance novel ever written in some new language, the words of which could only be spoken with four lips and two tongues together. 

Derek was transfixed. His hands fell to Stiles' bare waist, pulling their bodies as close as their mouths. His mouth chased after the electric contact as Stiles pulled back, his big, amber eyes meeting Derek's. 

"Thank you." It was spoken quietly, but with more sincerity than Derek had ever heard. 

He shook his head, replying in their four lipped language as he pulled them back together. Gratitude wasn't a part of this. Gratitude was for allies or friends. Stiles was pack, not only pack, he was Derek's mate. Mates meant there wasn't anything they wouldn't do to protect each other, no need to ask, no need to thank. 

Stiles crossed his arms behind Derek's neck, lifting onto the balls of his feet to match his torso height to Derek's in another attempt to reduce the space between them. Stiles understood. They couldn't love each other, not yet. But being mates was a bond mankind had no equivalent for. No matter how much or little you knew about each other you both knew two things.

You are mine. I am yours. 

They stood entwined in each other for a time neither of them cared to measure, smiling into their joined lips. Eventually, Derek broke the hold. Turning in Stiles' arms, he hoisted him up into a piggy back and clambered over the fence. Stiles laughed as his T shirts flew up as Derek jumped down the other side, a belly-deep, honest noise. Derek wanted to make him produce that noise again, didn't think he could ever get tired of hearing it. 

Together they walked, hand in hand, to the end of the jetty and sat as Derek had done so many times over the summer, bare feet hanging into the cool water. Stiles rested his head on Derek's shoulder, who rested his own head atop of Stiles', their faces turned up to catch the last of the day's rays. Neither of them spoke. They didn't need to. They both knew what they were waiting for. 

It was Derek who broke the silence. "I've decided what I want to do with my life." He announced. "I don't want to go to college or get a job in town. I want to teach sports, here at the lake."

Stiles turned his face to look up at Derek, hopefully. "Will you keep visiting me?" 

Derek raised one hand to stroke Stiles' cheek gently with his thumb, caressing the soft skin beneath his. "No." he whispered. "I want you to live with me." Stiles frowned, not understanding. "We can buy a little house by the lakeside, out of sight of the others. You can spend as much time with your clan as you like and my pack will only be across the preserve. Do you want that?" 

His breath hitched in his chest as he waited for Stiles to process his offer. "Yeah." he murmured. "I really want that." His sweet face broke into smile once more, Derek sighed in audible relief and kissed him again, harder. He fought with Stiles' tongue for dominance, nipping his lips between his teeth. He was Stiles' and more importantly, Stiles had agreed to be his! His hand gripped the back of his mates neck possessively. 

Stiles yelped and broke the connection. Derek worried he'd hurt him but Stiles wasn't looking at him. In the water floated two familiar faces, open with amazement. It was Scott and Lydia. Scott seized Stiles' wrist and pulled him into the water with a joyful click of his tongue, hugging his friend fiercely. Lydia held back but watched with intense curiosity as Stiles' gills opened in his neck, scales sprouting from his skin and fusing his legs. His flat teeth narrowed into their original needle like appearance and the webbing between his fingers grew out to the tips where otter like claws had sprung. 

A part of Derek wanted to grab Stiles back, to haul him from the water and keep him for himself. He didn't. Stiles needed to see his clan. He'd come back. 

"Visits as normal until I get the house sorted?" He raised one eyebrow at his mate, who was already trying to dunk Scott beneath the water, ruffling his wet hair playfully. 

Stiles nodded so hard Derek wondered how he didn't give himself whiplash. Derek leaned down so Stiles could press one last, parting kiss to his lips before tackling Scott and vanishing beneath the surface. Lydia rolled her eyes, reaching up to press her lips to Derek's cheek in silent thanks before flipping her dazzling red tail in air and following them out of sight. 

Just having him out of his line of vision made Derek want to howl for him to come back, but, it was okay. With a sigh he pushed himself to his feet and turned to walk back down the jetty to land and to his pack. 

\-----------------------------------------------------------------

Stiles stood in awe of the Hale house. 

It was a mansion in the dry woods, woods bigger than in any under the lake. They'd seen four legged prey creatures springing through the ground weeds and winged singers flutter among the high lily pads hanging from the many branches. It was another world. 

Stiles had been thrilled with their little two bedroom home by the water. By comparison the Hale house was like a palace. Derek had to pull him forwards and up the front steps as Stiles gaped a every detail. Stiles reached forward and pressed the pad of one long finger to the doorbell. A life without electricity meant that he still found even the simplest technology magical. His first driving lesson had been hilarious for Derek to watch. 

He smiled as the cheerful chimes rang, slipping his hand back into Derek's and squeezing it gently. 

After a moment the door opened to reveal the wide and slightly menacing smile of Derek's uncle. "Derek." he shook Derek's hand firmly. "Nice of you to join us for dinner. You're mother's been whining like a cub that you haven't been calling her ten times a day."

Derek rolled his eyes as Peter turned his attention to Stiles. "And I see you brought the fish course with you." He beamed. 

Derek opened his mouth to respond but was silenced as his uncles face fell, his eyes wide. Derek turned his head and saw Stiles, stood slightly behind him, wearing his best piranha smile of razor sharp blades. His mouth was open in a wide and terrifyingly toothy grin. 

Derek laughed, hard. Stiles' sheathed his teeth, widening them out into their blunter, flatter counterparts.

"How long have you been working on that one?"

He winked mischievously. Derek pulled him close and pressed a kiss to his temple.

They fitted together perfectly and Derek knew that Stiles was going to fit into their pack just as well. 

Which he did.


End file.
